PHYSIOLOGY
MUSCLE CONTRACTION
|
Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
|
Which of the following steps occurs first in muscle contraction?
|
|
Myosin globular head ‘uncoils’ releasing stored energy.
|
|
|
Cross Bridges are formed between actin and myosin
|
|
|
Tropomyosin changes shape (conformation) to expose myosin binding sites.
|
|
|
Calcium Binds with Troponin
|
Explanation:
Detailed explanation-1: -The first step in the process of contraction is for Ca++ to bind to troponin so that tropomyosin can slide away from the binding sites on the actin strands. This allows the myosin heads to bind to these exposed binding sites and form cross-bridges .
Detailed explanation-2: -(2) Calcium binds to troponin C, which induces a conformational change in the troponin complex. This causes tropomyosin to move deeper into the actin groove, revealing the myosin-binding sites.
Detailed explanation-3: -Depolarisation and calcium ion release. Actin and myosin cross-bridge formation. Sliding mechanism of actin and myosin filaments. Sarcomere shortening (muscle contraction)
There is 1 question to complete.